With the rising price of gasoline, what risk would I be taking if I use the 87 Grade ( 89 or 90 ) for my 97 Disco? Will this damage the engine?

 

I'll let one of the moderators or supermembers chime in, but my '99 Disco which is a 4.0 has been running just fine on 87 octane for the last seven years or about 160K miles without any problems whatsoever. I bought it with about 28K miles on it and she's at 190K now.

I'd be interested in hearing the same about the owners of my latest acquisition, the 4.4 BMW engine in my '03 RR.

Thanks All

 

87 octane will cost you at least 2 MPG, and the possibility of carbon build up on your valves along with generally low performance.
This last post is the first person who actually brags about lower power and mileage to save a few cents.
It will cost you more in maintance and repairs then what you save in gas.

 

If you actually break it down and think about it...it's simply not worth it.

Check it out:

My '01 Range has a 24 gallon tank. If I fill up at 3.60/gal with 87 its $88.20 a tank. If I put in premium, 93 octane around here, at 3.80/gal (avg of 10 cents more per octane level), it's $93.10 a tank.

That's a grand total of $4.90 I save by using regular. That means, with just those gas savings, it would take me 18 full tanks to save the cost of one fill up. Me filling up once every two weeks, that means 36 weeks to really save any money, or 9 months of cheaper gas to see any worthwhile amount of savings.

You'll save more money by just using premium gas, getting the best preformance you can out of the engine. On top of that if you do a standard tune up, air up your tires, and reduce unneccesary weight, you will gain AT LEAST 1 mpg....that's an extra 24.5 miles per tank I can go, and at ~15 mpg, that's a savings of $6.21 EACH TANK.

So, if you can save more money by maintaining your truck, doing what Land Rover reccomends, and with even the SLIGHT potential of engine damage down the road, why would you put in regular?

 

I've been using the cheapest gas on my 89 Classic for 9 years with absolutely no problems. It's a kick *** desert-prepped real off road Range Rover with a suspension lift, 285/75/16 Good Year MTRs, Bilstein shocks, full 6 point roll cage, Flomaster muffler, K+N air cleaner and on and on. What I'm getting at is that I go on some desert excursions through the highest sand dunes in North America (Altar Desert- Sonora Mexico) a few times a year and I can't have problems. Some of the climbs and drops we go through will make a lot of Rover drivers **** their pants, by the way.

The only reason I would see using the higher octane is if the engine's compression ratio or cylinder pressure demanded the detonation suppressants of the higher octane to keep it from over heating or pinging. Too many people mistakenly believe that higher octane means the gas has more "power" or "performance". On the contrary, it burns slower and creates less heat and power. The only way it would feel like more performance is if lower octane was causing problems for the engine; the higher octane would help suppress the detonation issues and thus obviously run better. Well why do race engines run on high octane race fuel? Because they need it. The race engine makes high horsepower because of the cam, heads, compression etc. not BECAUSE of the high octane fuel. The high octane fuel is needed so the performance engine can live. Try running 112 octane racing gas on a stock motor with about 8 or 9 to 1 compression ratio and check out the performance. Not! It will run like crap.

It's true that because the higher octane gas burns slightly slower (between 87 and 91) you may get slightly better fuel mileage, but we're talking minimal. Someday, I'd like to try and experiment and see what it translated to in MPG and $.

The only few times I've used premium were when I knew conditions were going to be exceptionally ruthless as far as ambient temperature (Hot) and engine operating temperatures- high loads and slow driving. Here, I could use the detonation suppressants in the higher octane.

The reason Land Rover recommends the higher octane is because it's safer for them that you don't hurt the motor in preignition and detonation situations as easily sitting in traffic with the AC on and the water temp approaching 260 F.

Think about this: Land Rover has been claiming king of the African deserts and jungles and Malasian rain forests etc. for decades. Well what kind of high octane quality gasoline do you think is available in these harsh places of the globe???

 

"
Think about this: Land Rover has been claiming king of the African deserts and jungles and Malasian rain forests etc. for decades. Well what kind of high octane quality gasoline do you think is available in these harsh places of the globe???"
Currently gas in South Africa is about 64 cents a gallon with the current exchange for 97 octane, a little more for the good gas.
So much for that theory.

 

It's not really the higher octane that gives better preformance, it's that the gasoline is more refined, with additives to keep the engine clean. This means the fuel burns more efficiently than low end gas.

The problem is that if you get a good gas station (I prefer Shell) that supplies good gas, even their low end will be relatively pure, and 87 octane won't leave the buildup that bottom of the barrel gasolines at 87 octane will leave. This is why alot of people are fine using low octane in the engines, and some arn't.

I refer you to my previous post....why risk it?

 

You mean $.64 a LITER. At 64 cents a gallon it would be cheaper than water. Even for a liter that sounds low. I don't know where you're getting your information from, but if they're rioting to the death in Egypt over high fuel costs right now, I don't see them giving it away for 64 cents a gallon in South Africa to the general public. No way. The dollar is not at it's strongest right now, but come on. From my personal travels, I know that Mexico is not as remote and F-up as African nations and high octane gas is not readily available. Mexico is not as reliant on foreign oil as the US so gas is a little cheaper, but not no 64 cents a gallon.

Wolf, you said, "You'll save more money by just using premium gas, getting the best preformance you can out of the engine." then you say "It's not really the higher octane that gives better preformance, it's that the gasoline is more refined". Which is it? I guarantee you that going from 87 to 93 on a dynamometer will not gain you jack horsepower. I also guarantee you that the difference in refining alone between the two octane level fuels won't show a microscopic difference in a Land Rover engine.

If the higher octane fuel is more refined then it costs more to make and thus is more expensive to buy, right. Then why would they needlessly refine it to 97 octane in South Africa like Mike sais? So everybody can run 10.5 to 1 high performance engines or what?

You can run what the heck you want, I'm just telling you real life.

 

I have to say the low octane fuel will not hurt your engine, as long as its from a reputable dealer. The more expensive gasoline is a better quality product, redardless of its octane rating, which is moreimportant in high perf,high compression or tuned motors. I use premium,or mid grade if Im broke In my 97 range. We all expect the best parts and oils for are beloved cars! why should gas be the exception.

 

As a person who has spent absorbant amounts on engine repair,I'll spend the extra dime for premium rather pay extra few bucks at fill up,then a few thousand in repair bills,the premium also keeps engine cleaner and running at full efficency the way it was to run